Chitemene has been well described by several authors (e.g. Peters, 1950; Trapnell, 1953; Stromgaard, 1989). It is a form of ‘slash-and-burn’ cultivation, but is unique in that the lopped area is much larger than the cropped area. There is some evidence that the system is indigenous to the Zaire-Zambezi watershed, and that it was brought from that area during migrations in the 17th century (Stromgaard, 1989). Although there are variations described by Stromgaard (1989), the basic (or ‘large-circle’) form of chitemene is as follows. Branches are lopped from trees within the selected area betwen July and September, laid out to dry, and before the beginning of the rains in November, are gathered into a heap in the centre of the cut area. In general, the area of a heap is around 0.4 ha (Trapnell, 1953), while the size of the cut area depends on the quantity of woody biomass in that area; where the regeneration period is long (30 years), it may be around 4 ha, but for shorter fallow periods may be as high as 11 ha (Peters, 1950). The heap is burnt just before the first rains, with finger millet (Eleusine coracana (L.) Gaertn.) usually being the first crop sown in the ash plot. The subsequent cropping sequence varies, but typically is groundnut (Arachis hypogaea L.), millet and beans (Phaseolus vulgaris L.) (see Trapnell, 1953). Often cassava (Manihot esculenta Crantz) is planted as an intercrop with the millet in the first year and harvested gradually from the third year onwards. When the field is exhausted after 4-5 years, it is abandoned and traditionally left fallow for 20-30 years (Mansfield, 1973), and another field opened. Mansfield et al. (1975) estimated that the chitemene system could support between 2 and 4 persons per square km depending on the amount of suitable land available. Nearly 90% of farmers in the high rainfall region practise chitemene.
In the north-eastern part of the region, where the population is higher and there are fewer trees, the Mambwe people have developed the fundikila or ‘grass-mound’ system of cultivation. Detailed descriptions of the fundikila process are given by Stromgaard (1988). It has been suggested that the system is a culmination of the breakdown of the chitemene system as the area became deforested by an increasing population (Stromgaard, 1989). Briefly, the process involves the formation towards the end of the rainy season of mounds of grass (predominantly Hyparrhenia filipendula and Pennisetum purpureum) covered by earth on a previously fallowed site. The grass rots within the mound during the dry season, and at the start of the next rains the mounds are levelled, and the finger millet planted. This may be followed in the second season by a variety of crops including maize (Zea mays L.), beans, sorghum (Sorghum bicolor L. Moench) and groundnuts. Millet is usually planted again in the third year, followed by a legume. In some cases, the field may be mounded every second year, and the crop planted on the mounds. This combination of green-manuring and alternating cereal crops with legumes helps to slow the exhaustion of soil fertility. There is some evidence that the system is sustainable (Stromgaard, 1990), but in practice the cropping period is 3-5 years, and the fallow period is traditionally up to 20 years (Mansfield, 1973). It has been estimated that the fundikila system is able to support 20-40 persons per square km (Mansfield et al., 1975), considerably more than the chitemene system.
Hybrid maize production
In order to meet the ever growing urban demand for maize meal in Zambia, government agricultural policy since independence has aimed at increasing national maize production. In Northern Zambia, in the last decade in particular, this policy has focused on promoting maize production by the small-scale farming sector through subsidised schemes involving the use of hybrid varieties and imported fertiliser (Stromgaard, 1984). In addition, there was a rapid population increase during 1970-1980 in the region, causing pressure on the traditional chitemene and fundikila systems of shifting cultivation, and forcing many subsistance farmers to intensify their farming practices (Chidamayo, 1987). Population density in some areas of present-day Northern Province has been recorded at 12 persons per sq. km (Stromgaard, 1985), well above the chitemene capacity of around 2-4 persons per sq. km (Mansfield et al., 1975). As a result of both of these factors, maize production, based on official figures, increased from 18,000 tonnes in 1978 to almost 160,000 tonnes in 1988, representing 11% of total marketed maize in Zambia. Production of soybean has also been promoted, and is often grown in rotation with maize. The growing of hybrid maize using imported fertiliser has been promoted in Zambia in recent years in an attempt to meet the country’s expanding demand for food. The maize growing programme, however, has been criticised for being too dependent on government subsidies and for its marketing system being too costly. At present, there is a heavy dependence on donor support for investment and running costs, and there is concern that the government will not be able to maintain the production and marketing infrastructure when donors phase out. In addition, there is evidence that maize yields are falling despite increased fertiliser application (Bolt & Holdsworth, 1987), possible reasons being a worsening in the timing of fertiliser supply, and increase in continuous maize monocropping with lack of crop rotation practices, or the acidifying effect of some chemical fertilisers. To compound the issue, subsidies on fertiliser and seed were removed in 1990, and maize production opened to market forces, exposing farmers in the remoter areas of the province to competition on the same terms as those closer to the points of consumption and input supply. Many small-scale farmers, unable to afford inputs, are now returning to the traditional chitemene and fundikila systems of cultivation.
Anticipation of these developments made it clear that to sustain maize production in the region, there was an urgent need to initiate research into alternative methods of soil fertility management other than the use of fertilisers. Biological methods of maintaining soil fertility, and alley cropping in particular, were suggested as potential solutions to the problem (AFRENA, 1989). The use of trees to enhance fertility is not a new concept to the subsistance farmers of Northern Zambia; the traditional chitemene shifting cultivation practice predominant in the region uses nutrients accumulated by trees of the miombo woodland. Alley cropping retains the basic principles of traditional bush fallowing, but attempts to keep all the land productive at the same time.
Article by Dr. Robin Mathews. Reproduced with permission from Dr. Robin Mathews Agroforestry in Zambia.